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Throttle cable increase


hardleydavidson
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Hi,


Weird one, I've just replaced my throttle cable and everything looks fine, the throttle operates as it should but when I turn the handlebars fully the throttle increases. Now I could understand if this was full left as it may stretch the cable but this only happens full right. There's nowhere for the cable to get caught or crimped and it's a simple run from the switch, under the tank to the carb.


Any ideas what could be causing this?

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Carefully follow the cable, have someone to turn your bars and inspect every part of the cable. You will probably find somewhere that cable is going over or below something where getting tide.

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All this pulling off and comparing lengths is making my wonder what kind of deviants we are harbouring :scratch:

 

You only just wondering NOW. :roll:

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All this pulling off and comparing lengths is making my wonder what kind of deviants we are harbouring :scratch:

 

A bit slow are we??? :P

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We had an issue on a throttle cable on one of our engines at work.

They are designed to have a set difference in length between inner and outer.

When the cable was laid out straight, the difference was correct, however when the engine was fitted to a car the cable was routed from the pedal through the bulkhead into the engine bay, this required it to follow a natural series of bends. The type of outer cable used actually opened up and caused the difference in length to change and made the throttle open.

You could see the effect with the cable on the bench ,measured the length difference laid out straight , bend it slightly to replicate the car installation and you could see and measure a change of several mm.

The cable supplier changed the outer cable to another brand and this fixed it.

It was down to the coils on the outer cable opening out, when a good and bad outer were laid side by side the tightness of the outer cable coils was obvious.

May sound random but true.


I had to replace the throttle cable on the R1 a while ago, bought a pattern part ,it just about fitted but the friction in the cable made the throttle feel awful and not snap shut.Had to buy a genuine part in the end.

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We had an issue on a throttle cable on one of our engines at work.

They are designed to have a set difference in length between inner and outer.

When the cable was laid out straight, the difference was correct, however when the engine was fitted to a car the cable was routed from the pedal through the bulkhead into the engine bay, this required it to follow a natural series of bends. The type of outer cable used actually opened up and caused the difference in length to change and made the throttle open.

You could see the effect with the cable on the bench ,measured the length difference laid out straight , bend it slightly to replicate the car installation and you could see and measure a change of several mm.

The cable supplier changed the outer cable to another brand and this fixed it.

It was down to the coils on the outer cable opening out, when a good and bad outer were laid side by side the tightness of the outer cable coils was obvious.

May sound random but true.


I had to replace the throttle cable on the R1 a while ago, bought a pattern part ,it just about fitted but the friction in the cable made the throttle feel awful and not snap shut.Had to buy a genuine part in the end.

 

But this is why you have cable adjusters to compensate for things like this


The adjusters work on the outer sheath to make it longer or shorter to give you the required slack at the throttle

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We had an issue on a throttle cable on one of our engines at work.

They are designed to have a set difference in length between inner and outer.

When the cable was laid out straight, the difference was correct, however when the engine was fitted to a car the cable was routed from the pedal through the bulkhead into the engine bay, this required it to follow a natural series of bends. The type of outer cable used actually opened up and caused the difference in length to change and made the throttle open.

You could see the effect with the cable on the bench ,measured the length difference laid out straight , bend it slightly to replicate the car installation and you could see and measure a change of several mm.

The cable supplier changed the outer cable to another brand and this fixed it.

It was down to the coils on the outer cable opening out, when a good and bad outer were laid side by side the tightness of the outer cable coils was obvious.

May sound random but true.


I had to replace the throttle cable on the R1 a while ago, bought a pattern part ,it just about fitted but the friction in the cable made the throttle feel awful and not snap shut.Had to buy a genuine part in the end.

 

But this is why you have cable adjusters to compensate for things like this


The adjusters work on the outer sheath to make it longer or shorter to give you the required slack at the throttle

 

Yes true but if slack set with the bar's straight ahead then the cable shape changed by turning the bars it could change the slack as we observed at work.

Not saying this is the issue but OP seems out of ideas.

He could try setting the slack with bars turned right and see what happens?

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We had an issue on a throttle cable on one of our engines at work.

They are designed to have a set difference in length between inner and outer.

When the cable was laid out straight, the difference was correct, however when the engine was fitted to a car the cable was routed from the pedal through the bulkhead into the engine bay, this required it to follow a natural series of bends. The type of outer cable used actually opened up and caused the difference in length to change and made the throttle open.

You could see the effect with the cable on the bench ,measured the length difference laid out straight , bend it slightly to replicate the car installation and you could see and measure a change of several mm.

The cable supplier changed the outer cable to another brand and this fixed it.

It was down to the coils on the outer cable opening out, when a good and bad outer were laid side by side the tightness of the outer cable coils was obvious.

May sound random but true.


I had to replace the throttle cable on the R1 a while ago, bought a pattern part ,it just about fitted but the friction in the cable made the throttle feel awful and not snap shut.Had to buy a genuine part in the end.

 

But this is why you have cable adjusters to compensate for things like this


The adjusters work on the outer sheath to make it longer or shorter to give you the required slack at the throttle

 

Yes true but if slack set with the bar's straight ahead then the cable shape changed by turning the bars it could change the slack as we observed at work.

Not saying this is the issue but OP seems out of ideas.

He could try setting the slack with bars turned right and see what happens?

 

Which is why I said there is not enough slack and thats why the revs are raising


Regardless of length and the amount of slack if its still rising its not got enough slack


If the slack is out the recommended range then more investigation needs to be done


But before we all get carried away which is already too late :lol: :lol: give the cable more slack till the revs stop rising then check the amount of slack if its too much then start checking lengths etc :D

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Thanks guys,


Well it's a mystery, checked the only place it could get snagged or crimped and it was loose and free, checked it again whilst turning the bars the revs increased but again not snagging, removed the cable and ran it directly to the carb, no increase, re-routed it where it's supposed to be and hey presto no increase.


Makes absolutely no sense, but for now the issue has vanished.

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Thanks guys,


Well it's a mystery, checked the only place it could get snagged or crimped and it was loose and free, checked it again whilst turning the bars the revs increased but again not snagging, removed the cable and ran it directly to the carb, no increase, re-routed it where it's supposed to be and hey presto no increase.


Makes absolutely no sense, but for now the issue has vanished.

 

So you may well have put more slack in the cable this time then :lol:

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